Top roll for drawing mechanism



J 1957 L. M. COTCHETT 2,775,793

TOP ROLL; FOR DRAWING MECHANISM Filed Dec. 8, 1951 121 a.

fazveazi'or Zomaic M 6036238343,

United States Patent TOP ROLL FOR DRAWING MECHANISM Louis M. Cotchett, Whitman, Mass.

Application December 8, 1951, Serial No. 260,724

8 Claims. (Cl. 19-142) This invention relates to drawing rolls for the drafting of textile fibres and more particularly to top rolls of the so-called shell type. Rolls of this type as used in spinning and roving machines are characterized by the provision of an axle mounted in stationary relation in the machine frame, with sleeves having cots thereon and termed shell rolls which are rotatably mounted upon the stationary shaft or axle, and in this respect differ substantially from the older solid type rolls in which the whole roll is rotatably mounted in the machine frame by means of journals.

A Well known drawback in the use of such solid top rolls is the friction arising between the rotating surface of the neck of the solid top roll and the co-engaging stationary surface of the saddle which bears down on the neck to weight the roll, as well as that arising between the bearing surfaces of the journals and the slots in the cap bars which serve as bearings therefor. These bearing surfaces on the customary roll, being of cast iron or steel, have a relatively rapid rate of wear and become worn to such a degree as to impair their usefulness, with the result that the entire roll must be discarded because incapable of being effectively repaired. While accepted as a necessary incident of established manufacturing procedure, the replacement of worn-out rolls is still a substantial and continually recurring element of expense in the industry.

To prevent intolerably rapid wear of the necks and journals of the rolls, lubrication must be supplied; but the lubricant used must be applied with the utmost restraint and accuracy to the bearing surfaces alone, both because the oil picks up the ever present lint and fly to collect on the necks and journals, under the saddle, and in the cap bar slots, checking rotation, and also because any spot or film of oil on the cots or on the fibrous material being drafted impairs the drawing or damages the material. Thus frequent cleaning of the rolls and saddles, and cleaning of the cap bars, is compelled by the accumulation of lint and fly when oil is used. Both the oiling and the cleaning entail constant expense.

While shell type top rolls comprising a stationary axle and shell rolls rotating thereon were devised to overcome these drawbacks, they have not solved all the problems, the plain bearing type because they still require oiling, and the ball bearing type because of their cost, and both are vulnerable to access of lint to the bearing surfaces with resultant interference with the essential steady rotation of the rolls.

It is the leading object of the present invention to provide a top roll construction in which these unfavorable features will be obviate. To this end the invention cornprises a shell type top roll in which the shell rolls are supported for rotation on the axle by bearing surfaces of special materials requiring little or no lubrication and formed-either on elements mounted in fixed relation in each shell roll or on integral portions of shell rolls which themeselves are made of such special materials, and in its preferred embodiment these shell rolls or elements, or at least their bearing surfaces, are formed of synthetic material characterized by superior frictional characteristics obviating the necessity for the use of a lubricant thereon. Additionally, means is provided to shield the bearing surfaces of such frictional elements from the entry of lint. Thus, the expenditure of time, effort, and care heretofore required for lubricating and for ridding the rolls of collected fly and lint caught by the lubricant are avoided or greatly reduced, and at a cost Fig. 3 is an axial section of one boss of still another alternative form.

In the embodiment illustrated in Fig. 1 the novel roll comprises a shaft or axle 1 to be mounted in the cap-bars of the spinning or roving frame in stationary relation, and two shell rolls 3, preferably of metal, rotatably mounted thereon in proper spaced relation to suit the gage of the particular frame in which these rolls are used. Each shell roll 3 has a shell 5 on which tubular cots 7 of rubber, leather or other suitable composition are adhesively mounted, and in accordance with the invention is equipped with special bushings 9 characterized by having a coefficient of friction so low that the application of a lubricant thereto is unnecessary. These bushings are pressed into recesses 10 in the ends of the interior bore 12 of the shells to fit tightly and immovably therein, and the interfaces, the interior surfaces,

of these bushings constitute the low-frictional bearing surfaces which engage the full diameter surface of the shaft 1.

Examples of preferred materials of this special lowfriction class forming the bushings 9 are the high molecular weight synthetic plastic compounds such as the polyamide polymers described in Letters Patent of the U. S. A.

No. 2,130,948, of which the material supplied under the name of nylon by E' I. DuPont de Nemours Co., Wilmington, Delaware, U. S. A., and a related synthetic plastic material supplied by them under the trade name of Teflon, are especially suitable; also the polyvinyl series of resins, ethyl cellulose, cellulose acetate, and others.

To hold the shell rolls 3 in properly spaced relation, a sleeve 11 is provided of sufficient length to exceed the Width of the saddles (not shown) of the weighting mechanism engaging therewith and used to weight the top roll, and comprises the sole spacing element interposed between the rolls on the shaft. Sleeve 11 fits closely but freely upon shaft 1, and is made of metal, no relative rotation occurring between the sleeve and shaft. Extending within the shells 5, it braces and stiffens shaft 1 against bending under the burden of the saddle. Both ends are flanged at 27 and reduced in outside diameter beyond the flanges, for purposes made plain later herein.

To hold the described parts of the roll in place, each extremity of shaft 1 is reduced and threaded as indicated at 13. An internally threaded metallic end cap- 15 is screwed onto each threaded end of the shaft 1, and secured thereto by means of a short screw 17 screwed into the threaded bore of the cap 15 to seat against the end of the shaft 1. Each cap 15 has an enlarged portion or flange 19 fitting closely within the recess 10 of the shell 5 of the proximate roll 3 which flange is formed with a rabbet 29 in which is mounted an annular lint seal 21,

preferably made of felt, held.- under compression by a combined retaining ring and thrust washer 23 of metal Patented Jan. 1, 1957 e located between the inner end of each end cap and the adjacent nylon bushing 9. These felt rings 21 are in wiping contact with the inner surface of the shell, thereby preventing the entry of lint into the outer end of each shell roll. The ends of spacer sleeve 11, fitting closely within the recess of the inner end of each shell, are similarly rabbeted to receive their felt lint seals 25, backed by rings identical with 23, thus preventing entry of lint at the inner end of each shell roll.

As is obvious, the cylindrical surfaces of the members engage the slots of the cap-bars (not shown) to mount the roll in the machine. The shaft 1 is held in the capbars against rotation by pressure of the saddle.

From the foregoing it will be seen that rolls of various lengths to suit various gages of frames are made up of the same shells 5, cots 7, bushings 9 and members 15, by merely employing different lengths of shafts 1 and spacer sleeves 11. It will likewise be evident that in the event of injury or wear requiring replacement of any or all of the bearing surfaces, the roll can be quickly and easily taken apart by unscrewing one or both of the members 15 to release the parts, followed by replacement of those which need renewal with new members.

The nature of the preferred materials used to provide the bearing surfaces of the bushings 9 makes them capable of running without undue wear in the total absence of applied lubricant, or with unprecedentedly small amounts in cases where abnormal weighting makes lubrication necessary.

In the alternative form of Fig. 2 the entire shell 41 of each shell roll 43 is made of nylon, Teflon, or other suitable low-friction synthetic plastic compound as indicated above, molded to the desired external and internal dimensions where the plastic admits, or else finished to such dimensions by subsequent operations. The bore 45 of the shell fits closely but freely upon stationary axle 44 and the material of the shell thus engages directly with the surface of the axle and forms the bearing surface between the shell and the axle. As in the form of Fig. 1, the extremities of the passage 45 within the shell are recessed or counterbored at 47 to receive the flanged ends of sleeve 49 and of end cap 51, with felt rings 53 confined in the rabbets 55, 57, of the sleeve and end cap respectively, and metallic washers 59 between the extremities of the sleeve and end cap and the opposing shoulders 61 within the bore of the sleeve. Cot 63 is cemented to the outside of shell 41.

In cases where some lubrication is required, as because of heavy weighting of the top rolls or on account of the characteristics of the particular plastic used for the shells, the construction of Fig. 3 is employed, in which the passage through the shell 65 is recessed as shown at 67 at midlength of the shell to form a storage chamber to hold a supply of grease for lubricating the bearing surfaces formed by the portions 69 at each end of the shell and comprising integral bushings corresponding to the bushings 9 of Fig. 1, the inward faces of which portions form the bearing surfaces of the shell and engage the surface of axle 71. The same fibrous washers 73 with their adjacent metallic washers 75 are provided in connection with the sleeve 77 and end cap 79, such washers 73 in this form additionally retaining the grease within the shell roll as well as keeping out lint and fly from the bearing surfaces. Cot 81 is adhesively aflixed to the outside of shell 65. Endcaps 79 are secured on the shaft ends just as in Fig. 1.

In the form of Fig. 1, the space within passage 12 between the two bushings 9 is likewise used to hold a supply of grease when lubrication becomes necessary.

While I have illustrated and described certain forms in which my invention may be embodied, I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore,I do not wish to be limited to the particular form shown, or to the details of construction thereof, but

What I do claim is:

1. A top roll for the drawing mechanisms of spinning and roving frames comprising in combination a stationary axle, a shell roll rotating about such axle, a cot on the shell roll, bushings of low frictional coefficient obviating necessity for lubrication mounted on the inside of the shell in sliding contact with the axle, and felt seals at the extremities of the bushings in wiping contact with the shell preventing the access of lint.

2. A top roll for the drawing mechanisms of spinning and roving frames, comprising in combination a stationary axle, a shell roll, a cot on the shell roll, and bushings of low frictional coefficient obviating the necessity of lubrication fixed in the shell roll and forming the bearing surfaces supporting the shell roll rotatably on the shaft.

3. A top roll for drawing mechanisms of spinning and roving frames, comprising in combination a stationary shaft, a shell roll rotating about such shaft, a cot on the shell roll, and bushings of synthetic material having a low coefficient of friction obviating need for lubricant mounted on the inside of the shell in contact with the shaft.

4. A top roll for the drawing mechanisms of spinning and roving frames, comprising in combination a stationary shaft, a shell roll, bushings of synthetic low-frictional material fixed in the shell roll and engaging and rotating about such shaft, the latter having a reduced end portion extending outwardly from such shell roll, such end portion being provided with a cap, an annular shield within the shell roll abutting the end of the cap, and a metallic thrust washer abutting the bushing cooperating with the shield in preventing the access of lint to the bushings.

5. A top roll for the drawing mechanisms of spinning and roving frames, comprising in combination a stationary shaft, a pair of shell rolls rotatably and detachably mounted on the shaft, a spacer mounted on such shaft holding the shell rolls in axially spaced relation, bushings of lowfrictional synthetic material fixed within recesses in the ends of the shell rolls and engaging the shaft, cots on the shell rolls, and felt seals at each extremity of the shell rolls preventing access of lint between the bushings and the shaft.

6. A textile top roll having in combination a stationary axle, two shells rotating about such axle, and a sleeve on such axle between the shells holding the latter spaced apart and adapted for engagement by a weighting saddle, the shells having fixed bearing surfaces engaging with such axle and formed of synthetic plastic material of in herently low coefiicient of friction.

7. A textile top roll according to claim 6 in which the said material composes both the shell and its bearing surfaces.

8. A textile top roll according to claim 6 in which the bearing surfaces are integral parts of the shell.

References Cited in the file of this patent UNITED STATES PATENTS 1,742,553 Motte Jan. 7, 1930 2,228,406 Schmidt Jan. 14, 1941 2,246,086 Austin June 17, 1941 2,246,092 Gilman June 17, 1941 2,355,511 Cobb Aug. 8, 1944 2,525,592 Cotchett Oct. 10, 1950 2,671,934 Rulon-Miller Mar. 16, 1954 2,674,012 Noelting Apr. 6, 1954 2,678,473 Butler May 18, 1954 2,678,474 Butler May 18, 1954 FOREIGN PATENTS 214,291 Great Britain Apr. 14, 1924 364,444 Italy Nov. 5, 1938 OTHER REFERENCES Nylon in Bearings and Gears, Product Engineering, July 1950. Pages 102-107.

Top Rolls Bushed with Nylon, Textile World, August 1949. Page 166. 

